Eukaryotes exon-intron structure

To continue the thoughts that were interrupted by the comets as to why this unpredictability. Examining the nucleic acids from different places, similarity seemed extensive even between samples that came from widely separate spots. There are only four main components in addition to odd occasional nucleotides and that did not make for much variation, and the idea offered itself that life would eventually be read from any nucleic acid by cut and paste processes in line with energy minima. That might be the origin of exon/intron structures in eukaryotes.7... 

In contrast to the genes of prokaryotes, for which the coding sequences are continuous, those of eukaryotes are present in blocks (exons) separated by intervening noncoding sequences (introns). Gilbert (1978) who introduced these terms, suggested that exon/intron structure could provide a mechanism for increasing the rate of evolution. It was pointed out that if, for example, exons corresponded to units of protein function, recombination within introns could reassort protein functions to... 

Long, M., de Souza, S.J., Gilbert, W. (1995) Evolution of the intron-exon structure of eukaryotic genes. Curr. Opin. Genet. 

INTRON A region of a gene (i.e., ENA) that is transcribed in the synthesis of RNA, but enzymatically removed (by "splicing") from the final mRNA before its translation into an amino acid sequence in protein introns are characteristic of gene structure in eukaryotic, but not prokaryotic, cells. (See also EXON and CODING SEQUENCE)... 

Structures of prokaryotic and eukaryotic primary transcripts (mRNAs). Prokaryotic mRNAs are polygenic, do not contain introns or exons, and are short lived in the cell. Eukaryotic mRNAs are monogenic, contain introns and exons, and usually are long lived in the cell. 

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